Perception systems and methods for identifying and processing a variety of objects

ABSTRACT

A drop perception system is disclosed that includes an open housing structure having an internal volume, an open top and an open bottom, and a plurality of perception units positioned to capture perception data within the internal volume at a plurality of locations between the open top and the open bottom of the open housing.

PRIORITY

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 62/269,640 filed Dec. 18, 2015, the disclosure ofwhich is hereby incorporated by reference in its entirety.

BACKGROUND

The invention generally relates to perception systems, and relates inparticular to scanning systems for use in connection with robotic andother sortation systems that are intended to be used in dynamicenvironments requiring the robotic or other sortation system toaccommodate processing a variety of types of objects.

For example many order fulfillment operations achieve high efficiency byemploying a process called wave picking. In wave picking, orders arepicked from warehouse shelves and placed at locations (e.g., into bins)containing multiple orders that are sorted downstream. At the sortingstage individual articles are identified, and multi-article orders areconsolidated, for example into a single bin or shelf location, so thatthey may be packed and then shipped to customers. The process of sortingthese articles has traditionally been done by hand. A human sorter picksan article from an incoming bin, finds a barcode on the object, scansthe barcode with a handheld barcode scanner, determines from the scannedbarcode the appropriate bin or shelf location for the article, and thenplaces the article in the so-determined bin or shelf location where allarticles for that order have been defined to belong. Automated systemsfor order fulfillment have also been proposed. See for example, U.S.Patent Application Publication No. 2014/0244026, which discloses the useof a robotic arm together with an arcuate structure that is movable towithin reach of the robotic arm.

Other ways of identifying items by code scanning either require manualprocessing, or require that the code location be controlled orconstrained so that a fixed or robot-held code scanner (e.g., barcodescanner) can reliably detect it. Manually operated barcode scanners aregenerally either fixed or handheld systems. With fixed systems, such asthose used at point-of-sale systems, the operator holds the article andplaces it in front of the scanner so that the barcode faces the scanningdevice's sensors, and the scanner, which scans continuously and decodesany barcodes that it can detect. If the article is not immediatelydetected, the person holding the article typically needs to vary theposition or rotation of the object in front of the fixed scanner, so asto make the barcode more visible to the scanner. For handheld systems,the person operating the scanner looks for the barcode on the article,and then holds the scanner so that the article's barcode is visible tothe scanner, and then presses a button on the handheld scanner toinitiate a scan of the barcode.

Automatic barcode scanners are similarly either fixed or hand-heldsystems, and the same principles apply. In the case of barcode scannerstypically used in industrial applications, the possible positions ofbarcodes must be tightly controlled so that they are visible to the oneor more scanners. For example, one or more barcode scanners may beplaced in fixed locations relative to a conveyor so that they can scanitems, typically boxes, as they pass by scanners. See, for example, U.S.Pat. No. 5,495,097. In these installations the range of placement of thebarcodes is comparatively limited as the barcodes are on labels affixedto one of four sides or top or bottom (e.g., if upside down) of a box,which can be presented using simple mechanical means, at orientationsoptimal for scanning.

In all of these cases, the systems employ sensors, cameras or laserreflectivity sensors, as well as software to detect barcodes and decodethem. These methods have inherent limitations that include the range ofdistances of orientations relative to the detection system, over whichthey are able to reliably scan barcodes. Firstly, the barcode must befacing the scanner; secondly the range to the barcode must be such thatindividual elements can be reliably distinguished; and, thirdly, thetilt and skew of the barcode must be such that individual elements canbe reliably distinguished. The types of sensors employed, and therobustness of the software detection and decoding schemes determinethese performance parameters.

There remains a need, therefore, for an object identification system forrobotic and other sortation systems that is able to accommodate theautomated identification and processing of a variety of objects in avariety of orientations.

SUMMARY

In accordance with an embodiment, the invention provides a dropperception system that includes an open housing structure having aninternal volume, an open top and an open bottom, and a plurality ofperception units positioned to capture perception data within theinternal volume at a plurality of locations between the open top and theopen bottom of the open housing.

In accordance with another embodiment, the invention provides aperception system for assisting in identifying an object, the perceptionsystem including a plurality of perception units that are eachpositioned to be directed toward different portions of an object paththat an object takes as the object travels through the perception systemwithout assistance by any mechanical conveyance system in contact withthe object.

In accordance with a further embodiment, the invention provides a dropperception system for identifying an object, the drop perception systemincluding a plurality of perception units that are each positioned to bedirected toward different portions of an object path that an object maytake as the object falls through the drop perception system, and eachperception unit is engageable to provide perception data regarding theobject.

In accordance with a further embodiment, the invention provides a methodof sorting objects. The method includes the steps of dropping an objectinto a perception system that includes a plurality of perception unitsthat are each positioned to be directed toward different portions of apath that the object may take as the object falls through the perceptionunit, and engaging the perception units to capture perception dataassociated with the object.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description may be further understood with reference tothe accompanying drawings in which:

FIG. 1 shows an illustrative isometric diagrammatic view of a perceptionsystem in accordance with an embodiment of the present invention;

FIG. 2 shows a front illustrative diagrammatic view of the perceptionsystem of FIG. 1;

FIG. 3 shows an illustrative isometric diagrammatic view of a perceptionsystem in accordance with another embodiment of the present invention;

FIG. 4 shows an illustrative elevated rear view of the perception systemof FIG. 3;

FIG. 5 shows an illustrative front view of the perception system of FIG.3 taken along line 5-5 thereof;

FIG. 6 shows an illustrative side view of the perception system of FIG.3 taken along line 6-6 thereof;

FIG. 7 shows an illustrative top view of the perception system of FIG.3;

FIG. 8 shows an illustrative linear diagrammatic view of a portion ofthe inside of the perception system of FIG. 3;

FIGS. 9A-9H show illustrative linear diagrammatic views of the inside ofthe perception system of FIG. 3 showing different stages of illuminationand perception data captures;

FIGS. 10A-10C show illustrative views of a flowchart showing anoperation of the perception system of FIG. 3;

FIG. 11 shows an illustrative diagrammatic view of a lighting systemused in the perception system of FIG. 3;

FIG. 12 shows an illustrative diagrammatic view of an image capturesystem used in the perception system of FIG. 3;

FIGS. 13A-13R show illustrative views of images taken by the perceptionsystem of FIG. 3 (FIGS. 13A, 13C, 13E, 13G, 13I, 13K, 13M, 130, 13Q) aswell as associated processed image data (FIGS. 13B, 13D, 13F, 13H, 13J,13L, 13N, 13P, 13R);

FIG. 14 shows a sortation system including the perception system of FIG.3 together with infeed devices and a sortation device;

FIG. 15 shows a sortation system including the perception system of FIG.3 together with an item position/orientation adjustment device includingan underside perception unit, as well as a sortation device; and

FIG. 16 shows a sortation system including the perception system of FIG.3 together with an item position/orientation adjustment device includinga fan, as well as a sortation device.

The drawings are shown for illustrative purposes only.

DETAILED DESCRIPTION

In accordance with an embodiment, the invention provides a novel objectperception system for the purposes of automatically sorting individualobjects in a set. In applications such as order fulfillment, articles orgoods are collected into heterogeneous sets and need to be sorted.Individual objects need to be identified and then routed toobject-specific locations. The described systems reliably automate theidentification of such objects by employing automated scanners. Thescanners look for a variety of codes such as indicia (e.g., barcodes,radio frequency tags, Stock Keeping Unit (SKU), Universal Product Code(UPC), Digimarc DWCode, etc.).

Operating in conjunction with a robotic pick and place system, systemsin accordance with various embodiments of the invention automate part ofthe sorting process, in particular the step of identifying pickedobjects. Instead of a person picking the object from a bin for example,a robotic arm picks an article from a bin. The object is passed in frontof a plurality of barcode scanners, and then, having obtainedidentification codes for the object, the object is then routed to theappropriate bin or shelf location. Since barcode scanners employ camerasor lasers to scan 1D or 2D symbologies printed on labels affixed toobjects, the barcodes must be visible to the scanner's sensors forsuccessful scanning in order to automatically identifying items in aheterogeneous stream of arbitrary objects, as in a jumbled set ofobjects found in a bin.

Whereas fixed industrial scanners require that the object's barcode besituated so that its barcode is visible to a scanner, the robotic arm ofthe present invention may pick an object out of a heterogeneouscollection of objects where the barcode is not visible and drop theobject into a perception system of the present invention. In otherembodiments, the system may provide that objects are dropped into theperception system by providing a feed conveyor positioned above theperception system, and providing that objects are singulated on theconveyor. The result is an automated barcode scanning system forarbitrary objects in a heterogeneous stream of objects that can be usedto accurately and reliably identify the objects.

Sorting for order fulfillment is one application for automaticallyidentifying objects from a heterogeneous object stream. Barcode scannershave a wide variety of further uses including identifying the stockkeeping unit of an article, or tracking parcels. The described systemsmay have many uses in the automatic identification and sortation ofobjects.

In accordance with various embodiments, therefore, the inventionprovides a method for determining the identity of an object from acollection of objects, as well as a method for scanning the barcode ofan object employing one or more scanners and a sortation system fordifferently processing different objects. The invention further providesa method for determining the placement of fixed barcode scanners so asto maximize the probability of successfully scanning an object selectedby a robot end-effector in accordance with certain embodiments, as wellas a method for determining whether multiple objects are dropped intothe scanner at the same time.

An important aspect is the ability to identify via barcode or othervisual markings of objects by employing a perception system into whichobjects may be dropped. Automated scanning systems would be unable tosee barcodes on objects that are presented in a way that their barcodesare not exposed or visible. As shown in FIG. 1, a perception system 10in accordance with an embodiment of the present invention may include anopen housing 12 through which an object may be dropped. Inside thehosing is a plurality of perception units 14 (e.g., eight or twelve)that are generally directed toward the interior of the housing from manydifferent directions. The housing may also include a plurality of lights16 that are timed to provide bright dispersed light at the times thateach of the perception units 14 take pictures of a falling object 18.Each perception unit 14 may, for example, take a hundred images while anobject is falling from directions as indicated at A in FIG. 2. Thedetection units 14 may be connected to a processing system 20 thatreviews each of the images in search of a unique identifier such as abarcode. The perception units may include cameras (e.g., 2D or 3D) orscanners (e.g., a laser reflectivity scanner other type of barcodereader (such as 1D or 2D barcode scanners, or radio frequency IDscanner), and the processing system 20 may include the associatedsoftware to process the perception data. Some cameras are directedhorizontally, while others are directed upward, and some are directeddownward as shown. The system 10 may also include entry detection unitsthat provide a curtain of, e.g., infrared illumination by a source 22across the opening as well as a detector 24 for detecting a break in theillumination. The detection units therefor provide a signal that anobject has entered the drop scanner 10.

The perception system may be used in certain embodiments, with a roboticsystem that may include a robotic arm equipped with sensors andcomputing, that when combined is assumed herein to exhibit the followingcapabilities: (a) it is able to pick objects up from a specified classof objects, and separate them from a stream of heterogeneous objects,whether they are jumbled in a bin, or are singulated on a motorized orgravity conveyor system; (b) it is able to move the object to arbitraryplaces within its workspace; (c) it is able to place objects in anoutgoing bin or shelf location in its workspace; and, (d) it is able togenerate a map of objects that it is able to pick, represented as acandidate set of grasp points in the workcell, and as a list ofpolytopes enclosing the object in space.

The allowable objects are determined by the capabilities of the roboticsystem. Their size, weight and geometry are assumed to be such that therobotic system is able to pick, move and place them. These may be anykind of ordered goods, packages, parcels, or other articles that benefitfrom automated sorting. Each object is associated with a stock keepingunit (SKU), which identifies the item.

The manner in which inbound objects arrive may be for example, in one oftwo configurations: (a) inbound objects arrive piled in bins ofheterogeneous objects; or (b) inbound articles arrive by a movingconveyor. The collection of objects includes some that have exposed barcodes and other objects that do not have exposed bar codes. The roboticsystem is assumed to be able to pick items from the bin or conveyor. Thestream of inbound objects is the sequence of objects as they areunloaded either from the bin or the conveyor.

The manner in which outbound objects are organized is such that objectsare placed in a bin, shelf location or cubby, into which all objectscorresponding to a given order are consolidated. These outbounddestinations may be arranged in vertical arrays, horizontal arrays,grids, or some other regular or irregular manner, but which arrangementis known to the system. The robotic pick and place system is assumed tobe able to place objects into all of the outbound destinations, and thecorrect outbound destination is determined from the SKU of the object.

It is assumed that the objects are marked in one or more places on theirexterior with a visually distinctive mark such as a barcode orradio-frequency identification (RFID) tag so that they may be identifiedwith a scanner. The type of marking depends on the type of scanningsystem used, but may include 1D or 2D barcode symbologies. Multiplesymbologies or labeling approaches may be employed. The types ofscanners employed are assumed to be compatible with the markingapproach. The marking, either by barcode, RFID tag, or other means,encodes a symbol string, which is typically a string of letters andnumbers. The symbol string uniquely associates the object with a SKU.

The operations of the systems described above are coordinated by thecentral control system 20. This system determines from symbol stringsthe SKU associated with an object, as well as the outbound destinationfor the object. The central control system is comprised of one or moreworkstations or central processing units (CPUs). The correspondencebetween SKUs and outbound destinations is maintained by the centralcontrol system in a database called a manifest. The central controlsystem maintains the manifest by communicating with a warehousemanagement system (WMS).

During operation, the broad flow of work may be generally as follows.First, the system is equipped with a manifest that provides the outbounddestination for each inbound object. Next, the system waits for inboundobjects to arrive either in a bin or on a conveyor. The robotic systemmay pick one item at a time from the input bin, and may drop each iteminto the perception system discussed above. If the perception systemsuccessfully recognizes a marking on the object, then the object is thenidentified and forwarded to a sorting station or other processingstation. If the object is not identified, the robotic system may eitherreplace the object back onto the input conveyor and try again, or theconveyor may divert the object to a human sortation bin to be reviewedby a human.

The sequence of locations and orientations of the perception units arechosen so as to minimize the average or maximum amount of time thatscanning takes. Again, if the object cannot be identified, the objectmay be transferred to a special outbound destination for unidentifiedobjects, or it may be returned to the inbound stream. This entireprocedure operates in a loop until all of the objects in the inbound setare depleted. The objects in the inbound stream are automaticallyidentified, sorted, and routed to outbound destinations.

In accordance with an embodiment therefore, the invention provides asystem for sorting objects that arrive inbound bins and that need to beplaced into a shelf of outbound bins, where sorting is to be based on aunique identifier symbol. Key specializations in this embodiment are thespecific design of the perception system so as to maximize theprobability of a successful scan, while simultaneously minimizing theaverage scan time. The probability of a successful scan and the averagescan time make up key performance characteristics. These key performancecharacteristics are determined by the configuration and properties ofthe perception system, as well as the object set and how they aremarked.

The two key performance characteristics may be optimized for a givenitem set and method of barcode labeling. Parameters of the optimizationfor a barcode system include how many barcode scanners, where and inwhat orientation to place them, and what sensor resolutions and fieldsof view for the scanners to use. Optimization can be done through trialand error, or by simulation with models of the object.

Optimization through simulation employs a barcode scanner performancemodel. A barcode scanner performance model is the range of positions,orientations and barcode element size that a barcode symbol can bedetected and decoded by the barcode scanner, where the barcode elementsize is the size of the smallest feature on the barcode. These aretypically rated at a minimum and maximum range, a maximum skew angle, amaximum pitch angle, and a minimum and maximum tilt angle.

Typical performance for camera-based barcode scanners are that they areable to detect barcode symbols within some range of distances as long asboth pitch and skew of the plane of the symbol are within the range ofplus or minus 45 degrees, while the tilt of the symbol can be arbitrary(between 0 and 360 degrees). The barcode scanner performance modelpredicts whether a given barcode symbol in a given position andorientation will be detected.

The barcode scanner performance model is coupled with a model of wherebarcodes would expect to be positioned and oriented. A barcode symbolpose model is the range of all positions and orientations, in otherwords poses, in which a barcode symbol will expect to be found. For thescanner, the barcode symbol pose model is itself a combination of anarticle gripping model, which predicts how objects will be held by therobotic system, as well as a barcode-item appearance model, whichdescribes the possible placements of the barcode symbol on the object.For the scanner, the barcode symbol pose model is itself a combinationof the barcode-item appearance model, as well as an inbound-object posemodel, which models the distribution of poses over which inboundarticles are presented to the scanner. These models may be constructedempirically, modeled using an analytical model, or approximate modelsmay be employed using simple sphere models for objects and a uniformdistributions over the sphere as a barcode-item appearance model.

FIG. 3 shows a perception system 30 in accordance with anotherembodiment of the present invention that includes a structure 32 havingan opening 34. The structure 32 includes a plurality of rows of sources(e.g., illumination sources such as LEDs) 36 as well as a plurality ofimage perception units (e.g., cameras) 38. The sources 36 are providedin rows, and each is directed toward the center of the opening. Theperception units 38 are also generally directed toward the opening,although, as with the embodiment of FIGS. 1 and 2, some cameras aredirected horizontally, while others are directed upward, and some aredirected downward. The system 30 also includes an entry source (e.g.,infrared source) 40 as well as an entry detector (e.g., infrareddetector 42) for detecting when an object has entered the detectionsystem 30.

The LEDs and cameras therefore encircle the inside of the structure 32,and the cameras are positioned to view the interior via windows that mayinclude a glass or plastic covering (e.g., 44). The structure 32 may besuspended by loop hooks 46 or placed over an opening and hang bybrackets 48.

FIG. 8 shows a portion of the interior of the scanner 30, where thesections are show laid out linearly. The cameras 38′ each include acamera portion 50 as well as an angled mirror 52 that provides thedesired field of view within the structure 32. Similarly, FIGS. 9A-9Hdiagrammatically and linearly, show the interior of the structure 32within the scanning region. As soon as the entry detector 40, 42 sensesthat an item has entered the scanning region, the LEDs and camerasfollow a sequence of steps that capture many images. In particular, asshown at 51 in FIG. 9A, a first set of LEDs 36 are illuminated, and afirst set of cameras 38 are engaged to take a number of pictures (afirst set of images) of the interior of the scanner. As shown at 53 inFIG. 9B, a second set of LEDs 36 are illuminated, and a second set ofcameras 38 (in this case one camera) are engaged to take a number ofpictures (a second set of images) of the interior of the scanner. Asshown at 54 in FIG. 9C, a third set of LEDs 36 are illuminated, and athird set of cameras 38 are engaged to take a number of pictures (athird set of images) of the interior of the scanner As shown at 55 inFIG. 9D, a fourth set of LEDs 36 are illuminated, and a fourth set ofcameras 38 are engaged to take a number of pictures (a fourth set ofimages) of the interior of the scanner. As shown at 56 in FIG. 9E, afifth set of LEDs 36 are illuminated, and a fifth set of cameras 38 areengaged to take a number of pictures (a fifth set of images) of theinterior of the scanner. As shown at 57 in FIG. 9F, a sixth set of LEDs36 are illuminated, and a sixth set of cameras 38 are engaged to take anumber of pictures (a sixth set of images) of the interior of thescanner. As shown at 58 in FIG. 9G, a seventh set of LEDs 36 areilluminated, and a seventh set of cameras 38 are engaged to take anumber of pictures (a seventh set of images) of the interior of thescanner. As shown at 59 in FIG. 9H, an eighth set of LEDs 36 areilluminated, and an eighth set of cameras 38 are engaged to take anumber of pictures (an eighth set of images) of the interior of thescanner. Again, the openings in the structure through which the camerascapture images may include a transparent glass or plastic 44. Each ofthe rows of LEDs 36 may also include a covering of transparent glass orplastic that is separate from the glass or plastic 44 of the openings toavoid light being transmitted through the glass to any detectors 38.Also, the outside of the structure may be covered (except for the topand bottom openings) with a protective film 33 (e.g., an amber film) asshown in FIG. 5, that filters some of the wavelengths of the LEDs forthe protection of any persons in the area.

With further reference to FIGS. 10A-10C, the process begins (step 1000)with the entry detectors 40, 42 detecting whether an object has enteredthe scanner (step 1002). Once this happens, the first set of lights areturned on and the first set of cameras begin capturing images (step1004). The first sets of lights and cameras are then turned off. A firstset of captured images are then sent to a processing core for processing(step 1006). The second set of lights are turned on and the second setof cameras begin capturing images (step 1008). The second sets of lightsand cameras are then turned off. A second set of captured images arethen sent to another processing core for processing (step 1010). Thethird set of lights are turned on and the third set of cameras begincapturing images (step 1012). The third sets of lights and cameras arethen turned off. A third set of captured images are then sent to anotherprocessing core for processing (step 1014). The fourth set of lights areturned on and the fourth set of cameras begin capturing images (step1016). The fourth sets of lights and cameras are then turned off. Afourth set of captured images are then sent to another processing corefor processing (step 1018). The fifth set of lights are turned on andthe fifth set of cameras begin capturing images (step 1020). The fifthsets of lights and cameras are then turned off. A fifth set of capturedimages are then sent to another processing core for processing (step1022). The sixth set of lights are turned on and the sixth set ofcameras begin capturing images (step 1024). The sixth sets of lights andcameras are then turned off. A sixth set of captured images are thensent to another processing core for processing (step 1026). The seventhset of lights are turned on and the seventh set of cameras begincapturing images (step 1028). The seventh sets of lights and cameras arethen turned off. A seventh set of captured images are then sent toanother processing core for processing (step 1030). The eighth set oflights are turned on and the eighth set of cameras begin capturingimages (step 1032). The eighth sets of lights and cameras are thenturned off. A eighth set of captured images are then sent to anotherprocessing core for processing (step 1034).

The above process may be repeated any number, m, of times (e.g., 50)(step 1036). After all m repeats have finished, the system confirms thatthe item has exited the scanner (step 1038). The system then determineswhether any codes were found (step 1040), and if not reports and errorthat no codes were found (step 1046). If a codes was found, the systemcollects all codes found (step 1042) and determines whether all codesmatch each other (step 1044). If not, the system reports that more thanone item was placed in the scanner (step 1050). If all codes found matcheach other, the system determines whether more than one item was placedin the scanner (step 1048) by determining whether too much space existsbetween regions of an item. If so, the system reports that more than oneitem was placed in the scanner (step 1050). If not, the system reportsthe identification of the code that was found (step 1052) and engages asorting path associated with the code that was found (step 1054). If nocode was found (step 1046) or if the system detects that more than itemwas in the scanner (step 1050), the system may ask whether the operatorwishes to try the scan again (or may be programmed to do so) (step1056). If yes, then the system returns the item(s) to the input streamahead of the drop scanner (step 1058). If not, the system moves theitem(s) to a manual sort location for sorting by a person (step 1060).

FIG. 11 shows an illustrative diagrammatic view of the control systemfor the lights in the system of FIG. 3. In particular, a processor 62 iscoupled to the structure 32 such that a light controller 66 is directedby a timing unit 60 to provide lighting control signals to adistribution control unit 64 in the structure 32, where the distributioncontrol unit 64 provides individual control to each of the plurality ofsets of LEDs 36. As shown in FIG. 11, the processor 62 also includes acamera controller 74 that is coupled to the timing unit 60. The cameracontroller communicates via core processors 72 to camera controllers 70on the structure 32, and each camera controller communicates with sets68 of cameras 38. The controllers 70 control both the triggering of thecameras as well as receive captured image data for processing by each ofthe respective core processors 72. The results of the core processors 72are provided to an output identification unit 76.

FIGS. 13A-13R show captured images as well as associated processed imagedata for nine images during the movement of two items through the dropscanner of FIG. 3. In particular, no items are seen in FIG. 13A, and theassociated processing image data shown in FIG. 13B shows no signal. InFIG. 13C, an item appears in the image, and the associated processedimage data in FIG. 13D shows the image of the item. As shown in FIG.13E, a second item appears in the field of view, and the associatedprocessing image data shown in FIG. 13F shows the second item. In thisimage (as well as in the processed image data of FIGS. 13H and 13J), thesystem would detect that more than one item has been dropped in thescanner because too much area would appear between the two items. Asshown in FIG. 13G, the second item continues to appear in the field ofview, and the associated processing image data is shown in FIG. 13H.Similarly, as shown in FIG. 13I, the second item continues to appear inthe field of view but begins to move closer to the first item, and theassociated processing image data is shown in FIG. 13J. As shown in FIG.13K, the second item has moved even closer to the first item, and theassociated processing image data is shown in FIG. 13L. As shown in FIGS.13M and 130, the second item has moved very close to the first item, andthe associated processing image data is shown respectively in FIGS. 13Nand 13P. FIG. 13Q shows that the items are leaving or have left thescanner, and the associated processing image data is shown in FIG. 13R.The capture of multiple images is therefore important to identifyingwhether more than one item is presented at one time in the scanner 32.

As discussed above, the output of the processor provides a signalindicative of the identified code of the item in the scanner, and basedon this, a sortation system may immediately take action consistent withhaving the item routed in the desired direction or processing path. Forexample, FIG. 14 shows a sortation system employing a scanning unit ofFIG. 3. Items may be dropped into the scanner by any means, such as butnot including a robotic arm 86 (dropping an item 84) or an inputconveyor 90 (dropping an item 88). In the case of a robotic arm 86, theend effector may employ deflection sensors 85 for detecting whether theitem 84 is moving (e.g., swinging) with respect to the robotic arm 86(and if so, wait until the movement ceases) prior to dropping the iteminto the scanner 32.

The scanner 32 is coupled to the processor 62 as discussed above, and anoutput sortation control signal 63 is provided to a sortation system,such as for example, a controller 96 of a conveyor 94 that providesdirection routing of items (e.g., 92) to any of a plurality of bins,containers or locations 98, 104, for example by moving in eitherdirection as indicated at C. Items 100 and 102, for example had beenrouted to location 98, and item 106 had been routed to location 104.

The system may also include an interrupting system that interrupts thefalling of an object through the perception system. The interruptingsystem may be useful, for example, where the item to be scanned is aplastic bag (either opaque or transparent), and particularly, where theidentifier code (such as a barcode) is not visible or readily visible bythe perception units, for example if the bag is folded and obscures thebarcode. With reference to FIG. 15, in this case, the interrupterelement may cause the bag to become flattened by an interrupter plate120. The interrupter plate 120 may include a further detection unit 124under a transparent window in the interrupter element 120 to detectidentifier indicia that is facing the interrupter element, as well aslights 126 that are illuminated when the detection unit 124 is capturingimages as discussed above. The interrupter unit 120 may also be providedon a hinged stand 122 that permits the interrupter element to be movedinto or out of the path of an item falling from the scanning unit 32.The interrupter unit 120 may be provided inside of or below the scanningunit 32. Again, the scanner 32 is coupled to the processor 62 asdiscussed above, and an output sortation control signal is provided to asortation system, such as for example, a controller of a conveyor 94that provides direction routing of items (e.g., 92) to any of aplurality of bins, containers or locations 98, 104, for example bymoving in either direction as indicated at C.

In other embodiments, the system may include an interrupting elementthat urges lighter items upward in a reverse direction for a short time.With reference to FIG. 16, in this case, the interrupter element maycause a light bag to be urged upward by a fan 144 attached to a motor142 that provides upward air pressure through a screen 140. The fan 144may be provided inside of or below the scanning unit 32. Again, thescanner 32 is coupled to the processor 62 as discussed above, and anoutput sortation control signal is provided to a sortation system, suchas for example, a controller of a conveyor 94 that provides directionrouting of items (e.g., 92) to any of a plurality of bins, containers orlocations 98, 104, for example by moving in either direction asindicated at C.

Those skilled in the art will appreciate that numerous modifications andvariations may be made to the above disclosed embodiments withoutdeparting from the spirit and scope of the present invention.

What is claimed is:
 1. A drop perception system comprising: an openhousing structure having an internal volume, an open top and an openbottom; and a plurality of perception units positioned to captureperception data within the internal volume at a plurality of locationsbetween the open top and the open bottom of the open housing.
 2. Thedrop perception system as claimed in claim 1, wherein the plurality ofperception units includes a plurality of cameras.
 3. The drop perceptionsystem as claimed in claim 3, wherein the plurality of perception unitsincludes a plurality of scanners.
 4. The drop perception system asclaimed in claim 3, wherein the plurality of scanners are radiofrequency ID scanners.
 5. The drop perception system as claimed in claim3, wherein the plurality of scanners are barcode scanners.
 6. The dropperception system as claimed in claim 5 wherein each of the plurality ofscanners is a laser reflectivity scanner.
 7. The drop perception systemas claimed in claim 1, wherein the perception system further includes aplurality of illumination sources.
 8. The drop perception system asclaimed in claim 7, wherein the plurality of illumination sourcesinclude a plurality of LEDs.
 9. The drop perception system as claimed inclaim 1, wherein the perception system further includes an interrupterelement that is engageable by an object falling through the perceptionsystem for altering a position or orientation of the falling object. 10.A perception system for assisting in identifying an object, saidperception system comprising a plurality of perception units that areeach positioned to be directed toward different portions of an objectpath that an object takes as the object travels through the perceptionsystem without assistance by any mechanical conveyance system in contactwith the object.
 11. The perception system as claimed in claim 10,wherein the plurality of perception units include a plurality ofcameras.
 12. The perception system as claimed in claim 10, wherein theplurality of perception units include a plurality of scanners.
 13. Theperception system as claimed in claim 10, wherein the drop perceptionsystem includes at least one sensor system for detecting whether anobject has enter the detection unit.
 14. The perception system asclaimed in claim 10, wherein the plurality of perception units includeperception units at least at the bottom and central regions of theperception system.
 15. The perception system as claimed in claim 10,wherein the plurality of perception units includes at least oneperception unit that includes a mirror positioned to permit the at leastone perception unit to effectively be directed substantially along theobject path.
 16. The perception system as claimed in claim 10, whereinthe perception system is coupled to a sortation controller for assigninga routing path for the object responsive to perception data provided bythe perception units.
 17. A drop perception system for identifying anobject, said drop perception system comprising a plurality of perceptionunits that are each positioned to be directed toward different portionsof an object path that an object may take as the object falls throughthe drop perception system, and each perception unit being engageable toprovide perception data regarding the object.
 18. The drop perceptionsystem as claimed in claim 17, wherein the drop perception system iscoupled to a sortation controller for assigning a routing path for theobject responsive to the perception data.
 19. The drop perception systemas claimed in claim 18, wherein the sortation controller includes asortation conveyance unit that is positioned to receive the object fromthe drop perception system, the conveyance unit being adapted to movethe object to one of a plurality of locations.
 20. The drop perceptionsystem as claimed in claim 17, wherein said perception system includesmultiple-object detection means for detecting whether multiple objectsare dropped through the drop perception system at the same time.
 21. Amethod of sorting objects, said method comprising the steps of: droppingan object into a perception system that includes a plurality ofperception units that are each positioned to be directed towarddifferent portions of a path that the object may take as the objectfalls through the perception system; and engaging the perception unitsto capture perception data associated with the object.
 22. The method asclaimed in claim 21, wherein the method further includes the step ofproviding illumination within the perception unit toward the differentportions of the path that the object may take as the object fallsthrough the perception unit.
 23. The method as claimed in claim 21,wherein the step of engaging the perception units to capture perceptiondata and the step of providing illumination, are provided such thatdifferent perception units are engaged at discrete times, and differentillumination sources provide illumination at the discrete timesassociated with the different perception units.
 24. The method asclaimed in claim 23, wherein the discrete times provide that successivesets of perceived data are captured from perception units around theinterior of the perception system as the object falls through theperception system.
 25. The method as claimed in claim 21, wherein themethod further includes the step of assigning a routing path for theobject responsive to the perception data.
 26. The method as claimed inclaim 25, wherein the method further includes the steps of: receivingthe object from the perception system at a sortation conveyance unit;and moving the object by the sortation conveyance unit to one of aplurality of locations